Molded composite inner liner for metallic sleeves

ABSTRACT

Logging downhole exposes components of logging tools, for example, antennas to abrasive and erosive operating conditions. A protective sleeve may disposed about an antenna assembly to protect the antenna assembly for the downhole operating conditions. To permit transmission and receipt of signals by and too the antenna assembly, slots are formed or disposed in the protective sleeve. A non-conductive composite insert is formed in the slots to protect the internal components of the protective sleeve, for example, the antenna assembly, from the operation conditions. A non-conductive composite inner liner is formed in an annulus of the protective sleeve and adheres to the protective sleeve and the non-conductive composite insert. The non-conductive component insert and inner liner allow signals to be transmitted and received by the antenna assembly so that logging operations can be completed without undue delay and the expense of repairing or replacing worn or damaged components.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional Application Ser.No. 62/683,803 entitled “Molded Composite Inner Liner for MetallicSleeves,” filed on Jun. 12, 2018, the entire disclosure of which isincorporated herein by reference.

BACKGROUND

The present disclosure relates generally to wellbore operations and,more particularly, to a sleeve assembly for a downhole logging tool.

During drilling operations for the extraction of hydrocarbons, a varietyof recording and transmission techniques are used to provide or recorddata downhole, for example, from the vicinity of a drill bit.Measurements of the surrounding subterranean formations may be madethroughout drilling operations using downhole measurement and loggingtools, such as measurement-while-drilling (MWD) and/orlogging-while-drilling (LWD) tools, which help characterize theformations and aid in making operational decisions. Wellbore loggingtools make measurements that may be used to determine the electricalresistivity (or its inverse, conductivity) of the formations beingpenetrated, where the electrical resistivity indicates various featuresof the formations. Those measurements may be taken using one or moreantennas coupled to, within or otherwise associated with the wellborelogging tools.

Logging tool antennas are often formed by positioning coil windingsabout an axial section of the logging tool, such as a drill collar. Aferrite material or “ferrites” are sometimes positioned beneath the coilwindings to increase the efficiency and/or sensitivity of the antenna.The ferrites facilitate a higher magnetic permeability path (forexample, a flux conduit) for the magnetic field generated by the coilwindings, and help shield the coil windings from the drill collar andassociated losses (for example, eddy currents generated on the drillcollar). The antenna must be protected from the harsh downholeenvironment. Generally, the antennas are protected by positioning asleeve around the antennas to protect the antennas from abrasion anderosion while the downhole logging tool traverses the wellbore. As thesleeve interferes with the operation of the antennas, slots are formedin the sleeve to provide a dipole angle for the electromagnetic field ofthe antennas to penetrate the formation or object of interest. However,debris, fluids or other harmful materials could penetrate the slots anddamage the antennas. Typically, a non-conductive inner sleeve isinserted into the outer sleeve to cover the slots and protect theantennas or the slots could be filled with an epoxy. Both solutionsstill allowed for some erosion and exposure of the antennas to thedownhole environment. Both solutions increase costs, wear and tear anddecrease reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are included to illustrate certain aspects of thepresent disclosure, and should not be viewed as exclusive embodiments.The subject matter disclosed is capable of considerable modificationsalterations combinations, and equivalents in form and function, withoutdeparting from the scope of this disclosure.

FIG. 1 is a schematic diagram of an exemplary drilling system, accordingto one or more aspects of the present disclosure.

FIG. 2 is a schematic diagram of an exemplary wireline system, accordingto one or more aspects of the present disclosure.

FIG. 3A is a partial isometric view of an exemplary portion of awellbore logging tool, according to one or more aspects of the presentdisclosure.

FIG. 3B is a cross-sectional view of a sleeve assembly, according to oneor more aspects of the present disclosure.

FIG. 4 is a top cross-sectional view of a sleeve assembly, according toone or more aspects of the present disclosure.

FIG. 5 is an isometric view of a sleeve assembly, according to one ormore aspects of the present disclosure.

FIG. 6 is a partial cross-sectional view of a sleeve assembly, accordingto one or more aspects of the present disclosure.

FIG. 7 is a partial cross-sectional view of a sleeve assembly, accordingto one or more aspects of the present disclosure.

FIG. 8 is a partial cross-sectional view of a sleeve assembly, accordingto one or more aspects of the present disclosure.

FIG. 9 is a partial cross-sectional view of a sleeve assembly, accordingto one or more aspects of the present disclosure.

FIG. 10 is a flowchart of logging operation, according to one or moreaspects of the present disclosure.

DETAILED DESCRIPTION

The present disclosure relates generally to wellbore operations and,more particularly, to a protective sleeve assembly for antennas of awellbore logging tools used in hydrocarbon drilling operations.

Downhole environments may have harsh operating conditions such asabrasive and erosive fluids including liquids, solid particles, andother debris. During downhole logging operations, for example,measurement while drilling (MWD) and logging while drilling (LWD)operations, a downhole tool that includes an antenna may includesections that include an antenna for receiving data related to aformation of interest or any other object. These antennas aresusceptible to damage and catastrophic failure due to the harsh downholeoperating conditions. Thus, these antennas must be protected while atthe same time provided with the ability to obtain the desiredmeasurements or data.

The antenna may be protected by an outer sleeve. To provide adequateprotection from the downhole operating conditions, the outer sleeve isgenerally constructed using a metallic material that interferes with theoperation of the antenna. To provide for proper operation of theantenna, the outer sleeve comprises one or more slots that allow theantenna to transmit and receive signals to and from the downhole tool.However, the slots allow for erosion and abrasion, for example, from adownhole fluid. Typically, a non-conductive inner sleeve is inserted orpress-fit into the outer sleeve to provide protection for the antennaand the slots are filled with a non-conductive material. Filling theslots with a non-conductive material protects the antenna from thedownhole operating conditions but may not be adequate as thenon-conductive material is also susceptible to erosion and abrasion andtypically does not bind sufficiently to the inner sleeve. For example,the non-conductive material may comprise an epoxy that breaks, cracks orotherwise weakens during a downhole operation which reduces the life ofthe outer sleeve, the inner sleeve, the antenna or any combinationthereof and requires expensive and time-consuming repair or replacement.Further, the inner sleeve necessarily reduces the available space withinthe outer sleeve for the antenna and necessary corresponding components.Insertion of the inner sleeve also creates a gap between the innersleeve and the outer sleeve. Repairing the outer sleeve and the innersleeve with the epoxy filled slots may be time-consuming, expensive andlaborious and may result in delays for completing the downholeoperation.

According to one or more embodiments, a composite insert may be disposedor positioned within the slot that provides sufficient boding to theouter sleeve to protect the internal components of the outer sleeve,such as the antenna. A composite insert does not have gaps between theouter sleeve and the insert and is not as susceptible to the downholeoperating conditions as the previously used non-conductive material thatwas injected into the slots. The composite insert provides a reliableand cost-efficient protection for the components of the outer sleeve.

FIG. 1 is a schematic diagram of an exemplary drilling system 100 thatmay employ the principles of the present disclosure, according to one ormore embodiments. As illustrated, the drilling system 100 may include adrilling platform 102 positioned at the surface and a wellbore 104 thatextends from the drilling platform 102 into one or more subterraneanformations 106. In other embodiments, such as in an offshore drillingoperation, a volume of water may separate the drilling platform 102 andthe wellbore 104. Even though FIG. 1 depicts a land-based drillingplatform 102, it will be appreciated that the embodiments of the presentdisclosure are equally well suited for use in other types of drillingplatforms, such as offshore platforms, or rigs used in any othergeographical locations. The present disclosure contemplates thatwellbore 104 may be vertical, horizontal or at any deviation.

The drilling system 100 may include a derrick 108 supported by thedrilling platform 102 and having a traveling block 110 for raising andlowering a drill string 112. A kelly 114 may support the drill string112 as it is lowered through a rotary table 116. A drill bit 118 may becoupled to the drill string 112 and driven by a downhole motor and/or byrotation of the drill string 112 by the rotary table 116. As the drillbit 118 rotates, it creates the wellbore 104, which penetrates thesubterranean formations 106. A pump 120 may circulate drilling fluidthrough a feed pipe 122 and the kelly 114, downhole through the interiorof drill string 112, through orifices in the drill bit 118, back to thesurface via the annulus defined around drill string 112, and into aretention pit 124. The drilling fluid cools the drill bit 118 duringoperation and transports cuttings from the wellbore 104 into theretention pit 124.

The drilling system 100 may further include a bottom hole assembly (BHA)coupled to the drill string 112 near the drill bit 118. The BHA maycomprise various downhole measurement tools such as, but not limited to,measurement-while-drilling (MWD) and logging-while-drilling (LWD) tools,which may be configured to take downhole measurements of drillingconditions. The MWD and LWD tools may include at least one wellborelogging tool 126, which may comprise one or more antennas capable ofreceiving and/or transmitting one or more electromagnetic (EM) signalsthat are axially spaced along the length of the wellbore logging tool126. The one or more antennas are protected by a protective sleeveassembly as discussed below with respect to FIGS. 3A, 3B, 4, 5, 6, 7, 8.As will be described in detail below, the wellbore logging tool 126 mayfurther comprise a plurality of ferrites used to shield the EM signalsand thereby increase the azimuthal sensitivity of the wellbore loggingtool 126.

As the drill bit 118 extends the wellbore 104 through the formations106, the wellbore logging tool 126 may continuously or intermittentlycollect azimuthally-sensitive measurements relating to the resistivityof the formations 106, for example, how strongly the formations 106opposes a flow of electric current. The wellbore logging tool 126 andother sensors of the MWD and LWD tools may be communicably coupled to atelemetry module 128 used to transfer measurements and signals from theBHA to a surface receiver (not shown) and/or to receive commands fromthe surface receiver. The telemetry module 128 may encompass any knownmeans of downhole communication including, but not limited to, a mudpulse telemetry system, an acoustic telemetry system, a wiredcommunications system, a wireless communications system, or anycombination thereof. In certain embodiments, some or all of themeasurements taken at the wellbore logging tool 126 may also be storedwithin the wellbore logging tool 126 or the telemetry module 128 forlater retrieval at the surface upon retracting the drill string 112.

At various times during the drilling process, the drill string 112 maybe removed from the wellbore 104, as shown in FIG. 2, to conductmeasurement/logging operations. More particularly, FIG. 2 depicts aschematic diagram of an exemplary wireline system 200 that may employthe principles of the present disclosure, according to one or moreembodiments. Like numerals used in FIGS. 1 and 2 refer to the samecomponents or elements and, therefore, may not be described again indetail. As illustrated, the wireline system 200 may include a wirelineinstrument sonde 202 that may be suspended into the wellbore 104 by acable 204. The wireline instrument sonde 202 may include the wellborelogging tool 126 described above, which may be communicably coupled tothe cable 204. The cable 204 may include conductors for transportingpower to the wireline instrument sonde 202 and also facilitatecommunication between the surface and the wireline instrument sonde 202.A logging facility 206, shown in FIG. 2 as a truck, may collectmeasurements from the wellbore logging tool 126, and may includecomputing and data acquisition systems 208 for controlling, processing,storing, and/or visualizing the measurements gathered by the wellborelogging tool 126. The computing facilities 208 may be communicablycoupled to the wellbore logging tool 126 by way of the cable 204.

FIG. 3A is a partial isometric view of an exemplary portion 300 of awellbore logging tool 126, according to one or more aspects of thepresent disclosure. The portion 300 is depicted as including an antennaassembly 302 that can be positioned about a tool mandrel 304, such as adrill collar or the like and inserted, disposed or position in a sleeveassembly of the wellbore logging tool 126. The antenna assembly 302 mayinclude a bobbin 306 and a coil 308 wrapped about the bobbin 306 andextending axially by virtue of winding along at least a portion of anouter surface of the bobbin 306.

The bobbin 306 may structurally comprise a high temperature plastic, athermoplastic, a polymer (for example, polyimide), a ceramic, or anepoxy material, but could alternatively be made of a variety of othernon-magnetic, electrically insulating/non-conductive materials. Thebobbin 306 can be fabricated, for example, by additive manufacturing(for example, 3D printing), molding, injection molding, machining, orother known manufacturing processes.

The coil 308 can include any number of consecutive “turns” (for example,windings of the coil 308) about the bobbin 306, but typically willinclude at least a plurality (for example, two or more) consecutive fullturns, with each full turn extending 360 degrees about the bobbin 306.In some embodiments, a pathway for receiving the coil 308 may be formedalong the outer surface of the bobbin 306. For example, one or moregrooves may be defined in the outer surface of the bobbin 306 to receiveand seat the coil 308. In other embodiments, however, the outer surfaceof the bobbin 306 may be smooth or even. The coil 308 can be concentricor eccentric relative to a central axis 310 of the tool mandrel 304.

As illustrated, the turns or windings of the coil 308 extend about thebobbin 306 at an angle 312 offset from the central axis 310. As aresult, the antenna assembly 302 may be characterized and otherwisereferred to as an “antenna,” “tilted coil” or “directional” antenna. Inthe illustrated embodiment, the angle 312 is 45°, by way of example, andcould alternatively be any angle offset from the central axis 310,without departing from the scope of the disclosure.

FIG. 3B is a cross-sectional view of a sleeve assembly 350, according toone or more aspects of the present disclosure. A sleeve assembly 350comprises a locking mechanism 360, an outer sleeve 354, one or moreslots 358 and a non-conductive insert 356. The outer sleeve 354 maycomprise any material that includes properties that resist abrasion orerosion due to the downhole operating conditions. For example, the outersleeve 354 may comprise a metallic material. Outer sleeve 354 comprisesan annulus 352. An antenna coil 308 or portion 300 as discussed abovewith respect to FIG. 3A may be positioned, disposed or inserted in theannulus 352 of sleeve assembly 350. The locking mechanism 360 allows thesleeve assembly 350 to couple to one or more other assemblies, tools orportions of assemblies or tools.

The sleeve assembly 350 comprises one or more slots 358 distributed,formed, positioned or disposed about any one or more portions of thesleeve assembly 350. In one or more embodiments, the sleeve assembly 350may comprise one or more slots 358 distributed circumferentially at oneor more angles as illustrated in the isometric view 500 of the sleeveassembly 350 of FIG. 5. The one or more slots 358 may be any width orlength and may be at any angle, aligned axially with any axis, or at anyother orientation or positioning. In one or embodiments, the slots maybe of any dimension or shape including, but not limited to, rectangular,elongated, elliptical, key-shaped, spiraled, circular, or any othershape for dimension for any aperture or opening. In one or moreembodiments, the one or more slots 358 may comprise straight edges,beveled edges, angled edges or any combination thereof. For example,FIG. 8 illustrates a partial cross-sectional view of a sleeve assembly350 with an outer sleeve 354 that comprises a slot 358. The slot 358comprises an angled edge 810 at an angle or deviation of 820 from acentral axis of the outer sleeve 354. For example, FIG. 9 illustrates apartial cross-sectional view of a sleeve assembly 350 with an outersleeve 354 that comprises a slot 358 with a beveled edge 910. The slot358 comprises a non-conductive insert 356 that provides insert retentionat a top portion 920 and a bottom portion 930 of the slot 358. The oneor more slots 358 overlap with an antenna disposed in the annulus of theouter sleeve 354. For example, an antenna is aligned or at leastpartially aligned with one or more slots 358 such that the slot allowsthe antenna, such as an antenna illustrated in FIG. 3A, to function oroperate as the one or more slots 358 allow the antenna to transmit orreceive one or more signals to and from a formation of interest or anyother object.

A non-conductive insert 356 may be disposed or positioned in any one ormore of the one or more slots 358. The non-conductive insert 356 maycomprise a composite material. The non-conductive insert 358 comprises amaterial that does not substantially interfere with the functioning oroperation of an antenna, for example, as illustrated in FIG. 3A. Thenon-conductive insert 356 may be formed by any one or more processesincluding, but not limited to, molding, such as injection molding,subtracted machining, fusing, curing, bonding, masking, any othersuitable process or procedure, or any combination thereof. Thenon-conductive insert 356 adheres, bonds, cures, fuses, or otherwiseaffixes to the outer sleeve 354 such that no or only substantiallyinconsequential air gaps exists between the non-conductive insert 356and the outer sleeve 354.

FIG. 4 is a top cross-sectional view of a sleeve assembly, for example,sleeve assembly 350 of FIG. 3B, according to one or more aspects of thepresent disclosure. FIG. 4 illustrates one or more slots 358 disposed,positioned or otherwise distributed about an outer sleeve 354.

FIG. 6 is a partial cross-sectional view of a sleeve assembly, forexample, sleeve assembly 350, according to one or more aspects of thepresent disclosure. An outer sleeve 354 may comprise a slot 358. Theslot 358 may be filled, packed, plugged or otherwise sealed with anon-conductive insert 356 such that non-conductive insert 356 formsbonds 610 with the outer sleeve 354 as discussed above. The seal formedby the non-conductive insert 356 prevents exposure of one or morecomponents disposed or positioned in the annulus 352 of the outer sleeve354 to erosive or abrasion materials or fluids. The bond 610 may be achemical bond or a mechanical bond. In one or more embodiments, anon-conductive inner liner 620 may be formed in the annulus 352 of theouter sleeve 354 and adheres to the outer sleeve 354. For example,non-conductive inner liner 620 forms a bond 610 with the outer sleeve354. The non-conductive inner liner 620 may comprise a compositematerial. In one or more embodiments, the non-conductive inner liner 620comprises the composite material as the non-conductive insert 356. Thenon-conductive inner liner 620 may be formed by any one or moreprocesses including, but not limited to, molding, such as injectionmolding, subtracted machining, fusing, curing, bonding, masking, anyother suitable process or procedure, or any combination thereof. Thenon-conductive inner liner 620 adheres, fuses, bonds or otherwiseaffixes to the outer sleeve 354 such that no or only substantiallyinconsequential air gaps exists between the non-conductive inner liner620 and the outer sleeve 354. In one or more embodiments, non-conductiveinner liner 620 may be a sleeve that is circumferentially formed in theannulus 352. In one or more embodiments, non-conductive inner liner 620may be formed on one or more portions of or partially circumferentiallyformed on the outer sleeve 354 in the annulus 352, for example, asillustrated in FIG. 6. For example, the non-conductive inner liner 610is circumferentially disposed or positioned or otherwise formed in theannulus 352 to form a sleeve that adheres to the outer sleeve withoutany or with only inconsequential air gaps. FIG. 7 illustrates a partialcross-sectional view of a sleeve assembly 350, according to one or moreaspects of the present disclosure. For example, a non-conductive innerliner 620 may form a button-shaped or flanged insert 710. Thenon-conductive inner liner 620 provides additional structure to maintainthe placement or bonding of the inner insert 356 in the slot 358.

FIG. 10 is a flowchart of a logging operation, according to one or moreaspects of the present disclosure. At step 1002, a logging tool, such aslogging tool 126 of FIG. 1, is disposed in a wellbore 104 of a formation106. The logging tool 126 may comprise a sleeve assembly 350. An antennaof the sleeve assembly 350, such as antenna assembly 302 of FIG. 3, maybe aligned, at least partially, at step 1004 with a slot 358 disposed inor about an outer sleeve 354 of the sleeve assembly 350. At step 1008,the antenna communicates or transmits a signal through a non-conductiveinsert 356 disposed in the slot 358 to the formation 106. At step 1012,the logging tool 126 or an antenna of the logging tool 126 receives areturn signal. The non-conductive insert 356 comprises a compositematerial that permits transmission of the signal and receipt of thereturn signal. At step 1016, the return signal is logged, for example,by a logging facility 206, a surface receiver, a telemetry module 128 orany other logging or memory device. In one or more embodiments, thelogging tool utilizes mud telemetry to communicate the return signal tothe logging facility 206. In one or more embodiments, the transmittedsignal and the return signal are communicated through a non-conductiveinner liner comprised of a composite material.

Therefore, the disclosed systems and methods are well adapted to attainthe ends and advantages mentioned as well as those that are inherenttherein. The particular embodiments disclosed above are illustrativeonly, as the teachings of the present disclosure may be modified andpracticed in different but equivalent manners apparent to those skilledin the art having the benefit of the teachings herein. Furthermore, nolimitations are intended to the details of construction or design hereinshown, other than as described in the claims below. It is thereforeevident that the particular illustrative embodiments disclosed above maybe altered, combined, or modified and all such variations are consideredwithin the scope of the present disclosure. The systems and methodsillustratively disclosed herein may suitably be practiced in the absenceof any element that is not specifically disclosed herein and anyoptional element disclosed herein. While compositions and methods aredescribed in terms of “comprising,” “containing,” or “including” variouscomponents or steps, the compositions and methods can also “consistessentially of” or “consist of” the various components and steps. Allnumbers and ranges disclosed above may vary by some amount. Whenever anumerical range with a lower limit and an upper limit is disclosed, anynumber and any included range falling within the range is specificallydisclosed. In particular, every range of values (of the form, “fromabout a to about b,” or, equivalently, “from approximately a to b,” or,equivalently, “from approximately a-b”) disclosed herein is to beunderstood to set forth every number and range encompassed within thebroader range of values. Also, the terms in the claims have their plain,ordinary meaning unless otherwise explicitly and clearly defined by thepatentee. Moreover, the indefinite articles “a” or “an,” as used in theclaims, are defined herein to mean one or more than one of the elementthat it introduces.

What is claimed is:
 1. A sleeve assembly, comprising: an outer sleeve,wherein the outer sleeve comprises an annulus; a slot disposed in theouter sleeve; and a non-conductive insert formed in the slot, whereinthe non-conductive insert comprises a first composite material thatseals the slot.
 2. The sleeve assembly of claim 1, further comprising anantenna disposed in the annulus of the outer sleeve and at leastpartially aligned with the slot.
 3. The sleeve assembly of claim 1,further comprising a non-conductive inner liner formed in the annulus ofthe outer sleeve that adheres to the outer sleeve, wherein thenon-conductive inner liner comprises a second composite material.
 4. Thesleeve assembly of claim 3, wherein the non-conductive inner liner is asleeve that is circumferentially formed in the annulus.
 5. The sleeveassembly of claim 3, wherein the non-conductive inner liner comprises aflange that adheres to the non-conductive insert.
 6. The sleeve assemblyof claim 1, wherein the slot comprises a beveled edge.
 7. The sleeveassembly of claim 1, wherein the slot comprise a plurality of slotsdisposed circumferentially about the outer sleeve.
 8. A method ofassembling a sleeve assembly, comprising: disposing a slot in an outersleeve; forming a non-conductive insert in the outer sleeve, wherein thenon-conductive insert comprises a first composite material; and sealingthe slot with the non-conductive insert.
 9. The method of claim 8,further comprising disposing an antenna assembly within an annulus ofthe outer sleeve.
 10. The method of claim 9, wherein disposing theantenna assembly comprises aligning, at least partially, an antenna ofthe antenna assembly with the slot.
 11. The method of claim 8, furthercomprising disposing a non-conductive inner liner in the annulus of theouter sleeve such that the non-conductive inner liner adheres to theouter sleeve, wherein the non-conductive inner liner comprises a secondcomposite material.
 12. The method of claim 11, wherein disposing thenon-conductive inner liner in the annulus comprises forming a flangethat adheres to the non-conductive insert and the outer sleeve.
 13. Themethod of claim 11, wherein disposing the non-conductive inner liner inthe annulus comprises forming a sleeve circumferentially about theannulus such that the sleeve adheres to the outer sleeve and thenon-conductive insert.
 14. The method of claim 8, wherein disposing theslot comprises forming a plurality of slots circumferentially about theouter sleeve.
 15. The method of claim 8, wherein disposing the slotcomprises forming a beveled edged slot in the outer sleeve.
 16. Themethod of claim 8, wherein disposing the slot comprises forming anangled edge slot in the outer sleeve.
 17. The method of claim 8, whereinforming the non-conductive insert in the slot comprises at least one offusing, bonding, curing and molding the non-conductive insert to theouter sleeve.
 18. A method of logging in a wellbore of a formation,comprising: disposing a logging tool in a wellbore, wherein the loggingtool comprises a sleeve assembly; aligning an antenna of the sleeveassembly with a slot disposed about an outer sleeve of the sleeveassembly; transmitting a first signal from the antenna through anon-conductive insert disposed in the slot to the formation, wherein thenon-conductive insert comprises a first composite material; receiving afirst return signal associated with the transmitted first signal by thelogging tool; and logging the first return signal.
 19. The method ofclaim 18, wherein transmitting the first signal from the antennacomprises transmitting the first signal through a non-conductive innerliner disposed in an annulus of the outer sleeve that is adhered tonon-conductive insert, wherein the non-conductive inner liner comprisesa second composite material.
 20. The method of claim 18, wherein theslot comprises a plurality of slots disposed circumferentially about theouter sleeve.